The overall objective of this program is to commercially develop an innovative Intraoral Fluoride Releasing System (IFRS) for high-caries-risk patients which is superior to the currently marketed oral care products in that it does not depend on patient compliance for efficacy in preventing the development of dental caries. The broad objectives of this Phase II proposal are to prepare a new batch of IFRD with 0.24 mg/day fluoride release rate and to investigate the feasibility of using medical grade plastics for fabrication of the IFRD retainers. Specific objectives are to (l) determine the bioactivity and dose response of the fluoride released into the saliva from the IFRD's using an in situ remineralization model, (2) establish product safety, and (3) demonstrate clinical effectiveness of the IFRS with high caries-prone xerostomia patients. If the results are equal or better than the currently used therapeutic products, then clinical trials will be extended to high-caries-risk children and to xerostomia patients. After completion of the extended Phase III clinical studies, an NDA will be filed with the FDA and plans for commercialization of the IFRS to high caries risk subjects will be implemented.